Apparatus for control of electric motors.



No. 645,089. Patented Mar. I3,l |900'.

W. H. HAMLEN.

APPARATUS FOR CDNTRUL 0F ELECTRIC MOTORS.

(Application led Sept. 12, 189B (un Modem S TTU/NVE Y.

TH: Nonms persas co., Pnofouo., wAsmNoTcN, D. c.

UNITED STATES PATENT OFFICE.

\VELLS It. IIAMLEN, OF JOI'INSTOWN, PENNSYLVANIA, ASSIGNOR TO TIIE LORAIN STEEL COMPANY, OF PENNSYLVANIA.

APPARATUS FOR CONTROL oF EtEcTRlC MOTORS'.

sPEcIIrIcAIIoN forming part of Letters Patent No. Gespec, dated March 13, 1906.

Original application iiledrlpril19,1899J Serial No. 713,691. Divided and this application tiled September l2, 1899. lSerial No.7301207. (No modelli) To all whom t may concern:

tric motors, which is described and broadly claimed in my application, Serial No. 713,691, filed April 19, 1899, oit which the present application isadivision. That system, broadly considered, consists in shifting the motors from a series relation of their elements to a multiple relation by intermediate steps in which one element of each motor is connected in multiple with the correspondingelement of the other motor or motors, the other elements being in series. The apparatus herein described and claimed is designed to effect these and other minor circuit changes in a practical and satisfactory manner by the operation of a single lever.

Broadly considered, the invention consists in the combination, with a plurality of electric motors, of a controlling-switch and electrical connections, the switch having contacts arranged relatively to said connections to rst cut out one element of each motor and then connect one element of each in parallel with the corresponding element of the other or others,and other contacts to successively cut out one element of each motor, and to then conneet the motors as a whole in parallel.

The invention also consists in the combination, with a plurality of electric motors and artificial resistance for connection in circuit therewith, of a switch having contacts and electrical connections whereby the motors in starting from a position of rest may be connected with their elements all in series relation with each other and with the artificial resistance, and by further movement of the operating-lever will gradually cut the resistance out of circuit While maintaining the series relation of the motor elements, and by still further movement will connect one elementof each motor in multiple arc with the corresponding element of the other motor or motors, and will finally connect the motors as a whole in parallel.

The invention also consists in certain other novel features of construction and arrangement hereinafter described, and pointed out in the appended claims.

Referring to the accompanying drawings, Figure 1 is a diagram showing two, electric motors, a controller, and such parts of the Wiring and connections as serve to illustrate the nature and mode of operation of my invention. Fig. Qshows, diagra1nmatically,the successive circuit connections or changes made by the operation of the controllingswitch.

Referring to Fig. 1, the letters A' Azdesignate the armatures of the two electric motors, and F E2 the respective field-coils of said motors. Squares 1 to 13, inclusive, designate a series of xed contact-brushes, which form 75 part of the controlling-switch, the balance of which consists of a plurality of moving contacts-such, for instance, as contact-pieces mounted on a cylinder or drum arranged tol be rotated by an operating-lever. This type 8o of controlling-switch is old in the art in so far as its general mechanical construction is concerned, and I have shown only the electrical contacts and their connections. These contacts are represented by the rectangles 1a 85 to 26a and are divided into four dierent groups, each of which is electrically disconnected -from the others, but Whose individual contacts are each connected electrically to all the others of that group. Contacts 1 to 9, 9o inclusive, comprise one group, contacts 10a to 13a a second group, contacts 111a to 21, inclusive, athird group, and contacts 22a to 26, inclusive, a fourth group. Certain of the contacts, as 9a, 14a, 15a, 2 a, and 22, while be- 95 longing electrically to the groups in which they are above classified in point of position with respect to brushes, are included on a portion of the controller drum or cylinder which belongs otherwise to an adjacent group, roo

wl1e1-ebyce1tain of the brushes are designed to operate withV contacts of two different groups inVv different positions of the controller. Brushes 6, 7, and 11 are shown as being of this class, 'Y

The numerals 15 to 24-designate a series of brushes which constitute the fixed contact members Vof a reversing-switch, which is also providedrwith groups ofy movable contacts C. This switch and its connections form no part of the present invention and are shown only for the purpose of enabling the circuits to be traced. For this purpose it will be sufficient to consider only'the contacts C C2 O3 C4 C5, with which it will be assumed hereinafter that the brushes Y15 to 24 are in engagement.

The brush No. 1 is connected to the high potential or trolley side of the circuit (indicated at T) through the usual portions of the car-wiring and instruments. (Not shown.) Brush No. 2 is connected to brush No. 15 through an external resistance R and connections 2. Brushes 3 and 4 are also connected to brush l5 through portions of said resistance and connection 2G. brush 5 is also connected to brush 15 by connection 2C, brush G to brush 19 by connection 6c, brush 7 to brush 1S by connection 7, brush 8 to connection 2C by connection SC and resistances R2 R', brush 9 to brush 22 by connection 92, brush 10 to brush 24 through armature A and connections 10C, brush 11 to ground G2 through armature A2 and connections 11, and brush 12 to brush 23 by connection 12C. Brushes 16 and 17 are connected to each other through field F and conductors 16and 17c and brush 2O to brush 21 through field F2 and conductors 20c 21C. The dotted'yertical lines 1 2, tbc., indicate the several positions of the brushes 1 to 13 on the movable contacts in passing from a series to a multiple connection of the motors, and Fig. 2 shows, diagrammatically, the connection of the two motors and their elements at each position of the said brushes 1 to 13. At the first position of these brushes brushes 3, 4, 5, S, and 13 are not engaging any of the movable contacts, but brushes 1, 2, 6, 7, 9, 10, 11, and 12 are respectively in engagement with contacts 1, 2, 10, 12, 18, 19, 22, and 23, and the course of the current, assuming brushes 15 to 24 to be engaging the contacts O, G2, C3, O4, and C5, is as follows: from trolley T to brush 1, contacts l. 2, brush 2, resistance R', connection 2c, brush 15, contact C', brush 1G, connection 16C, field F', connection 17C, brush 17, contact C2, brush 1S, connection 7, brush 7, contacts 12 10a, brush 6, connection 6, brush 19, contact C3, brush 20, connection 20C, field F2, connection 21C, brush 21, Contact C4, brush 22, connection 9, brush 9, contacts 1S 19, brush 10, connection 10C, armature Af to brush 24, contact C5, brush 23, connection 120, brush 12 to contacts 23 22, brush 11, and connection 11c through armature A2 to ground i2. ln this position, therefore, the

current passes through the artificial resistance and through the field-magnets and armatures of both motors in series. shown in position 1 of Fig. 2. At the next position the only change made in the contacts is thatbrush 2 passes off the contact 2 and brush 3 becomes engaged with the contact 4%Y The effect of this change, it will be seen, is to cut out'V of the motor-circuit a portion of the artificial resistance R.VY No other changes are made in the circuit. At the third position brush 4 engages contact G and brush 3 has left contacts 4. The effect of this change is to cut ont still more of the resistance R without disturbing otherwise the circuit. In the fourth position brush 4 has left contact 6 and the brush 5 has engaged contact 7. The current now passes directly from the contact 1' to contact 7, to brush 5, connection 2, &c., as in the previous positions, resistance R', however, being entirely cut out. point itwill be noted that nothing but ordinary rheostatic regulation has been employed. In the fifth position brush 2 engages contact 3 and brush 8 engages contact 16; otherwise the points of contact are the-same as in position 4. The effect of these changes is that the current divides, one part passing from brush 5 through connection 2c and thence through both fields and armatures as before, and the other part passing through the resistance R', connection 8C, brush 8, contacts 1G and 19 to brush 10, and thence through both armatures in series. In this position the resistance is no longer used rheostatically, but is used as a shunt t0 the fieldwinding, so that the elds may be weakened and the counter electromotive force correspondingly decreased, thereby allowing more current to pass to the armatures and accelerate them. The next three positions are passover or temporary positions, and it is not deemed necessary to trace out the connections in detail. In the first of these positions (position G) the engagement of the brush 7 with the contact 14 (while still bridging into the contact 12) of the third group sh0rtcircuits the field F2, and by contact of the brush 13 with contact 25 the armature 'A2 is also short-circuited. The next position (by reason ofthe passing of the brush 7 from contact 12 wholly onto contact 14) breaks the circuit through field F2 and (by reason of the disengagement of brush 11 with contact 22) cuts out the armature A2. The eighth position by reason of the fact that the brush 7 again engages a contact of the second group (contact 13) once more puts the two fields in series, armature A2 remaining cut out. At the ninth position, which is an essential Working position and perhaps the most important feature of the system, lthe two fields remain in series, but the two armatures are coupled up in parallel. The parallel coupling of the armatures results in a considerable acceleration of the speed; but this is sufficiently counteracted by the series coupling of the two fields and their conse- This is Up to this IIO quent maximum resistance and abnormal strength to give no more than the desired amount of acceleration. Thus the first position in which the armatures are in parallel they are protected from receiving too great a rush of current not only because of the ohmic resistance of the two fields in series, but also by the counter electromotive force caused by the abnormally-strong elds. This change is effected by reason of the brush 11 being in engagement with the contact 2l of the fourth group, while brushes 12 and 13 remain in engagement with the contacts 23 and 25. By reason of this change the current is divided, part going by brush 10 and connection 10C to armature A' and thence to ground and the other part going by brush 1l and connection 11c through armature A2 to ground. In position 10, which is also a working or notch7 position, brushes 3 and S have engaged, respectively, t-he contacts 5 and 17 of the first and third groups, respectively, thereby throwing part of the resistance R' and resistance R2 in shunt to the fields F' F2, which remain in series with each other, armatures A' A2 also remaining in parallel with each other. The effect of this cha-nge is to again reduce the strength of the fields by providing an additional path for the current. Positions 11, 12, and 13 are temporary or passover positions. In position 1l the brushes 3 and S have left the contacts 5 and 17, thereby cutting the resistances R' R2 out of circuit. Brushes 12 and 13 have also left the contacts 23'25, thereby breaking the ground connection of the armature A'. In position 12 the brush 10 has left the contact I9, cutting out armature A', the current passing from contact 21 to brush 11 through the armature A2 to ground. In position 13 brush 5 has passed from the contact 7 of the first group and brush 6 has left contact 11 of the second group and engages contact 9 of the first group, thereby cutting out field F', the other contacts remaining the same as in the last position. Position 14 is the last position and brings the two motors as a whole in parallel with the fields and armatures of each motor in series. This is effected as follows: Brushes 1, 5, 6, 7, 9, 10,11, 12, and 13 are respectively engaged with contacts L, 8, 9, 15, 1S, 20, 2l, 24:, and 26. The course of the current is now from trolley T to contact L to contacts 8 9. Here it divides, one part passing by the brush 5, connection 2, brush 15, contact C', brush 16, connection 16, field F', connection 17, brush 17, contact C2, brush 1S, connection 7, brush 7, contact 15, contact 20, to brush 10, connection 10, through armature A', brush 24, contact C5, brush 23, connection 12, brush 12, contacts 24 26, and brush 13 to ground. The other part passes from contact 9 to brush 6, connection 6 to brush 19, contact O3, brush 20, connection 20, field F2, brush 21, contact O4, brush 22, connection 9, brush 9, Contact 1S to contact 21, brush 11, connection 11, and through armature A2 to ground.

It will be observed, therefore, that by the operation of my switch I start with the two fields and the two armatures connected in series with each other and with artificial resistance; that I gradually cut the resistance out of circuit while retaining the series connections of the motor elements; that I next use the same resistance in shunt with the motor-elds still in series 5 that I next pass rapidly through a series of preparatory changes in which first one field and one armature are short-circuited, then cut out, and, thirdly, the fields are connected in series with one armature to a working position within the two fields are connected in series with the two armatures in parallel; that I next throw the resistance into parallel with the two fields in series and the two armatures in parallel. Then by successive preparatory changes in which first one armature and then one field are cut out I bring the motors as a Whole to multiple relation. In this manner I am able with the waste of very little power in external resistance and by the movement of a single operating-lever to attain a gradual acceleration of the motors and without making at any time such an abrupt change as to injure the motors. It will also be observed that each of the four groups of contacts-has a special function to perform. The contacts of the first group control the resistance R' and the connections from the trolley to the reversingswitch and through the first field. The contacts of the second group control the second eld. The contacts of the third group control the resistance R2 and alsothe connection of armature A', while the contacts of the fourth group control the connection of the armature A' and also the ground connection. This arrangement of the contacts results in a simple contrivance, mechanically considered, and affords a means of carrying into application my improved method of control without unduly multiplying the circuit connections. I do not wish to be limited to immaterial and non-essential details involved in the switch as above described, it being obvious that many minor changes may be made therein Without 4departing from the spirit and scope of my invention as pointed out in the appended claims.

Having thus described my invention, what I claim, and desire to protect by Letters Patent, is-

1. The combination with a plurality of electric motors, and external resistance for connection in circuit therewith, of a controllingswitch having groups of contacts and electrical connections whereby the motor elements may be first connected all in series with each other and with the said resistance, and which, by further movement of the operatinglever will gradually remove the resistance from circuit while maintaining the series connection of the motor element, and subse- IOO i efiaos quently thereto, connect one element of each motor in multiple arc with the corresponding element of the other motor or motors and then connect the two motors as a whole in multiple arc.

2. The combination with a plurality of electric motors, of a controlling-switch and connections for shifting said motors from series to parallel relation, said switch having contacts arranged relatively to said connections to iirst cut out one element of each motor and then connect one element of one in parallel with the corresponding element of the other or others, and other contacts to successively cut out one element of each motor, and then connect said motors as a whole in multiple.

3. The combination with two motors and artificial resistance for connection in circuit therewith, of a controller-switch adapted to shift said motors from series to parallel relation, said switch having a group of contacts arranged to connect said resistance in circuit with the motors in series therewith and also as a shunt to the motor-fields, other contacts arranged to connect one element of one motor in parallel with the corresponding element of the other motor and at the same time maintain the series connection of. the other elements of the motors, and other contacts arranged to subsequently connect the said other elements in multiple.

4E. The combination with a plurality of motors, and artificial resistance for connection therewith, of a.controllingswitch adapted to change said motors from series to parallel relations, and having four groups of contacts which are electrically disconnected each group from the other, together with electrical connections, one of said groups being arranged to control the connection in circuit of the resistance, and of the first field, the second group arranged to control the connection of the second field, and the third group to control the connection of the first armature, and the fourth group to control the connection of the second armature.

5. The combination with two electric motors, of a controllingswitch therefor, co1n prising a series of brushes connections between said brushes and the working circuit, connections between pairs of said brushes and the fields of the two motors, and with one of the armatures, a connection between another of said brushes and the other armature, which is permanently grounded, and groups of contacts on said switch for engagement with said brushes, and arranged to connect the brushes in various ways to thereby connect the motor elements in series, or in multiple, or with an element of one motor in series with the corresponding element of the other motors, and lthe other elements in multiple.

In testimony whereof I have affixed my signature in presence of two witnesses.

WELLS R. HAMLEN.

Witnesses:

L. A. WILSON, ETHEL M. DE CAMP. 

